The car has been running very rough the last couple of weeks seems to be jerky under constant acceleration and this morning it stalled on me half way threw a right hand turn. The car has only been throwing one code - P0135, O2 sensor bank 1 sensor 1. Could a bad O2 sensor be the cause of all this? And if so, which one is bank 1 sensor 1 (I'm assuming driver side before the cats but I need verification).

 

You are correct,driver side,before the converter

 

P0135 indicates a faulty sensor heater circuit. That's the heater that helps heat the sensor up to working temperature, and holds it there under light engine loads. It could be a wiring harness issue, or a sensor issue. Swap the pre-cat sensors side-to-side and see if the problem follows the sensor (sensor problem) or stays on the driver's side (wiring problem).

If the sensor isn't staying hot, it may not be giving accurate readings, which could cause problems.

 

But if it's just a heater issue wouldn't it level out and be fine once the car warms up?

 

The code indicates there is a problem with heater circuit, based on the amount of time it takes the sensor to reach operating temperature, compared to programmed values. There are other codes for the sensor sensing element circuit and sensor switching speed. The diagnostic only runs once per cold start.

If the heater can't heat the sensor up fast enough, it may also not be able to keep the sensor warm enough under low load operating conditions. If you had headers, moving the sensors further from the engine, this might be a contributing factor, but its sort of hard to tell from your signature if that's the case.

 

I'm running the stock cats with some BBK shorty headers. Been running these headers for quite a few years with out any issues till now. Of course, I've never changed out the O2 sensors as long as I've owned the car so it's likly it is going out. I don't know. I'm just not sure what would cause the rough idle and running like crap thing since it's only throwing that one code.

 

I'm updated my sig to reflect the most important mods. I supose this weekend I'll take your advise and switch the O2s side to side to see where the issue is.